#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main() {
	FILE * fp;
	int i= 20, j= 30, k, n;
	fp= fopen("d1.dat", "w");
	fprintf(fp, "%d\n", i);
	fprintf(fp, "%d\n", j);
	fclose(fp);
	fp= fopen("d1.dat", "r");
	fscanf(fp, "%d%d", &k, &n);
	printf("%d,%d\n", k, n);
	fclose(fp);
}